Semiconductor device and method of forming a semiconductor device

ABSTRACT

A semiconductor device includes group III-V layers formed over a substrate. At least one of the group III-V layers is doped with a dopant. The dopant includes a first dopant and one of a second dopant and an isovalent impurity. The first dopant has a covalent radius different in size than the covalent radii of each of the second dopant and the isovalent impurity.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to doping semiconductor materials.

2. Description of Related Art

Group III-V semiconductors comprise elements selected from groups IIIand V of the periodic table. The group III nitride semiconductors, inparticular, are used as light emitters for optoelectronic deviceapplications. Group III nitride semiconductors can also be used forhigh-frequency, high-power, and/or high-temperature electronic devices.These types of semiconductors have the wide bandgap necessary forshort-wavelength visible light emission. There are known group IIInitride compounds and alloys comprising group III elements, such as Al,Ga and In, and the group V element N. These materials are deposited onsubstrates to produce layered structures usable in optoelectronicdevices, including LEDs and laser diodes. These devices emit visiblelight over a wide range of wavelengths.

One such group III-V semiconductor is GaN. GaN is a wide-bandgapsemiconductor that is used to fabricate blue-light emitting laserdiodes. These laser diodes require a region with n-type doping and aregion with p-type doping. N-type doping is usually achieved in GaNlasers by introducing Si atoms, which replace Ga atoms and act asdonors. P-type doping is usually achieved in GaN lasers by introducingMg atoms, which occupy the Ga sublattice sites and act as acceptors. Anactive region is located between the n-type region and the p-typeregion.

SUMMARY OF THE INVENTION

At present, doping levels in semiconductor materials are less thandesired for efficient semiconductor device performance. For example,hole concentrations in GaN resulting from p-type doping are usually lessthan a few times 10¹⁸ cm⁻³. Several factors may limit the holeconcentration. One factor is the low solubility of the Mg atoms. Anotherfactor is the high binding energy of the holes to the Mg acceptors.

This invention provides doped materials and methods for doping thatcompensate for local stress caused by dopant atoms having smaller orlarger covalent radii than that of the atoms of the sublattice in agroup III-V semiconductor material, such as a nitride semiconductormaterial.

This invention separately provides higher concentrations of dopant in alayer of a group III-V semiconductor material, such as a nitridesemiconductor material.

This invention separately provides semiconductor devices having enhancedefficiency.

In various exemplary embodiments, the semiconductor structure accordingto this invention includes at least one first group III-V layer, such asa group III nitride layer, formed over a substrate. At least a portionof the at least one first group III-V layer is doped by one of an n-typedopant and a p-type dopant. An active layer is formed on or over the atleast one first group III-V layer. At least one second group III-V layeris formed on or over the active layer. At least a portion of the atleast one second group III-V layer is doped by the other one of then-type dopant and the p-type dopant. A first electrode is formed on orover the at least one first group III-V layer, and a second electrode isformed on or over the at least one second group III-V layer. The p-typedopant includes a first p-type dopant and one or both of a second p-typedopant and an isovalent impurity. The first p-type dopant has a covalentradius different in size than that of the one of the second p-typedopant and/or the isovalent impurity. The first p-type dopant has acovalent radius that is one of less than or greater than the covalentradius of the base group III element, while the second p-type dopantand/or the isovalent impurity each have a covalent radius that isgreater than or less than, respectively, the covalent radius of the basegroup III element.

The local stress caused by the first p-type dopant is compensated by thelocal stress caused by the second p-type dopant and/or the isovalentimpurity. Because the local stress is reduced, the concentration of thefirst p-type dopant can be enhanced.

These and other features and advantages of this invention are describedin, or are apparent from, the following detailed description of variousexemplary embodiments of the systems and methods according to thisinvention

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of this invention will be described in detail,with reference to the following figures, wherein:

FIG. 1 shows the structure of a light-emitting device according to oneexemplary embodiment of the invention;

FIG. 2 illustrates a first step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention;

FIG. 3 illustrates a second step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention;

FIG. 4 illustrates a third step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention;

FIG. 5 illustrates a fourth step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention;

FIG. 6 illustrates a fifth step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention;

FIG. 7 illustrates a sixth step of one exemplary embodiment of a methodof forming an optoelectronic device according to this invention; and

FIG. 8 shows an example of a Te—Ga—P complex according to thisinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It should be understood that the following description of exemplaryembodiments of the invention can be directed to any type of known orlater discovered semiconductor structure and material. However, thefollowing exemplary embodiments of the invention are directed to nitridesemiconductor materials and light-emitting device structures usingnitride semiconductor materials. Specifically, the following descriptionis directed to GaN semiconductor structures. However, it should beappreciated that the techniques set out in the following description canbe directed to n-type or p-type doping of any known or later discoveredsemiconductor compound. For example, co-pending U.S. patent applicationSer. No. 09/849,233, filed May 7, 2001, pending at time of issueincorporated herein by reference in its entirety, is particularlydirected to p-type doping.

In the following description, the terms “doping” and “dopant” should beinterpreted to include the introduction of impurities, such as isovalentinpurities, into a semiconductor material and thus is not limited tointroducing donor or acceptor materials. It should be appreciated that,while the following description focuses on isovalent impurities, anyappropriate impurity could be used in place of the isovalent impurities.

FIG. 1 shows a multi-layered light-emitting device structure 100according to one exemplary embodiment of the invention. Thelight-emitting device structure 100 includes a substrate 110, which maybe formed by any known or later developed substrate material, such as,for example, sapphire or silicon carbide. In the case of sapphire, A andC-oriented single crystal sapphire is preferable for optoelectronicdevices. A first group III nitride layer 120 is formed over thesubstrate 110. Group III nitrides, such as GaN, InGaN, and AlGaN, havethe characteristic wide bandgap necessary for short-wavelengthvisible-light emission. At least a portion of the first group IIInitride layer 120 shown in FIG. 1 is an n-type doped region. An activelayer 130 is formed on or over the first group III nitride layer 120.Any suitable material can be used for the active layer, such as, forexample, InGaN.

A second group III nitride layer 140 is then formed on or over theactive layer 130. At least a portion of this second group III nitridelayer 140 is a p-type doped region. A first electrode 150 is formed onor over the second group III nitride layer 140. A second electrode 152is formed on or over the first group III nitride layer 120. Theresulting structure shown in FIG. 1 thus includes the active layer 130,which is confined between the p-type group III nitride region 140 andthe n-type group III nitride region 120.

In operation, an electric potential is applied across the firstelectrode 150 and the second electrode 152. Electrons in the conductionband flow from the n-doped group III nitride layer 120 to a lower energystate in the active layer 130. The voltage applied at the firstelectrode 150 causes holes in the valence band of the p-doped group IIInitride layer 140 to flow into the active layer 130. Thus, electronsfrom the n-doped group III nitride layer 120 combine with holes from thep-doped group III nitride layer 140 in the active layer 130.Recombination of holes and electrons in the active layer 130 results inthe emission of light.

Multiple confinement and contact layers can be provided within thelight-emitting device structure 100. Thus, the first and second groupIII nitride layers 120 and 140 are illustrative and are not meant tolimit the number of group III nitride layers which may be formed withinthe light-emitting device structure 100.

P-type doping has been achieved in GaN semiconductors by doping with Mgatoms. However, less than desired hole concentrations have been achievedwith Mg doping.

In one exemplary embodiment of a group III-V material usable with thisinvention, a GaN semiconductor is p-doped with Be and co-doped withanother p-dopant that has a larger covalent radius than that of Be.Computational results [J. Neugebauer and C. G. Van de Walle, J. Appl.Phys. 85, 3003 (1999)] have shown that the solubility of Be in GaN islarger than that of Mg, and the ionization energy of Be is slightlylower than that of Mg.

The formation energy directly determines the solubility of asubstitutional acceptor. The formation energy, in turn, is affected bythe strength of the bonding with the substitutional acceptor's nearestneighbors, and the size of the substitutional acceptor relative to theatom the substitutional acceptor replaces. In the case of an acceptorsubstituting on the group III site, the nearest neighbors are the groupV atoms. Thus, the bond strength of Be can be estimated by the heat offormation of Be₃N₂. Be₃N₂ has a much larger heat of formation than thatof Mg₃N₂. Rhe stronger Be—N bond, in comparison to Mg—N, favorablyaffects the solubility of Be compared to Mg in nitride-based group III-Vsemiconductors.

However, the relatively low formation energy of Be is counteracted bythe relatively small covalent radius of Be. Be has a much smallercovalent radius than the covalent radius of Ga. Thus, using Be as ap-dopant results in local strain in the Ga—N lattice due to sizablerelaxation of the nearest N neighbors. The local strain caused by the Beatoms is energetically costly and raises the formation energy of the Beatoms on the Ga sites. As a result, the Be formation energy in GaN dopedsolely with Be is actually only slightly lower than that of Mg. Thus,concentrations of Be on the Ga sites remain relatively low.

According to one exemplary embodiment of the group III-V materialaccording to this invention, higher concentrations of Be in the Galattice are achieved by introducing at least one second larger sizep-dopant and/or isovalent impurity into the Ga sites of the Ga—Nlattice. In general, the at least one second p-dopant and/or isovalentdopant or impurity has a covalent radius that is larger than the firstp-type dopant. This is especially useful when the first p-type dopanthas a covalent radius that is smaller than the covalent radius of thebase group III element. In this case, in various exemplary embodiments,the at least one second p-type dopant and/or covalent dopant or impuritycan have a covalent radius that is larger than the covalent radius ofthe base group III element. The small size of the Be atom is thuscompensated for by the larger size of another dopant in its vicinity.The stress compensation of the larger-sized atoms will result in a lowerformation energy of the dopant complex. This, in turn, results in higherconcentrations of Be in the Ga lattice.

Alternatively, in another exemplary embodiment, the at least one secondp-type dopant and/or isovalent dopant or impurity has a covalent radiusthat is smaller than the first p-type dopant. This is especially usefulwhen the first p-type dopant has a covalent radius that is larger thanthe covalent radius of the base group III element. In this case, invarious exemplary embodiments, the at least one second p-type dopantand/or isovalent dopant or impurity can have a covalent radius that isalso smaller than the covalent radius of the base group III element.

According to one exemplary embodiment of a group III-V materialaccording to this invention, the isovalent impurity, introduced as adopant along with Be, is In. The formation energy of a complex includinga Be atom with one or more In atoms located in second-nearest-neighborpositions is lower than that of an isolated Be atom. The reduction information energy by the addition of In enhances the concentration of Bein the Ga lattice.

According to a second exemplary embodiment of the group III-V materialaccording to this invention, the GaN semiconductor is doped with a smallgroup-II acceptor and co-doped with a larger group-II acceptor. Anexample of a suitable small group-II acceptor is Be. An example of asuitable large group-II acceptor is Mg. The Be and Mg atoms in the Galattice form a Be—N—Mg complex. The Be—N—Mg complex is a double acceptorcomplex.

According to a third exemplary embodiment of the group III-V materialaccording to this invention, the GaN semiconductor is doped with a largegroup-lI acceptor and co-doped with a small group-III; isovalentimpurity. An example of a suitable large group-II acceptor is Mg. Anexample of a suitable small group-III isovalent impurity is Al. The Mgand Al atoms in the Ga lattice form a Mg—N—Al complex. The Mg—N—Alcomplex is a single acceptor complex.

According to a fourth exemplary embodiment of the group III-V materialaccording to this invention, the GaN semiconductor is doped with a smallgroup-II acceptor and co-doped with a large group-V isovalent impurity.An example of a suitable small group-II acceptor is Be. An example of asuitable large group-V isovalent impurity is P. The Be and P atoms inthe Ga lattice form a Be—P complex. The Be—P complex is a singleacceptor complex.

The above exemplary embodiments of the group III-V material according tothis invention are not meant to be limiting. The doped materials anddoping methods according to this invention are intended to encompass anycombination of dopant and co-dopant in a region of a group III-Vsemiconductor material that results in stress compensation in a dopedgroup III-V layer or region of the group III-V semiconductor material.The doped materials and doping methods according to this invention canbe applied to any known or later discovered semiconductor compound, suchas, for example, GaAs and InP.

Thus, according to a fifth exemplary embodiment of the group III-Vmaterial according to this invention, a GaAs semiconductor is p-dopedwith Be and co-doped with In on the Ga site, or Sb on the As site.According to a sixth exemplary embodiment of the group III-V materialaccording to this invention, an InP semiconductor is p-doped with Be andAs isovalent impurities are introduced on the P site.

The doped materials and doping methods according to this invention canalso be used to enhance the concentration of n-type dopants in a regionof a group III-V semiconductor. Thus, according to a seventh exemplaryembodiment, a GaAs semiconductor is n-doped with Te and co-doped with asmaller sized co-dopant, such as, for example, S, on the As site.Alternatively, P isovalent impurities can be introduced on the Assublattice, or B isovalent impurities can be introduced on the Ga siteto compensate for the local stress caused by the larger Te atoms. Anexample of a Te—Ga—P complex in GaAs is shown in FIG. 8.

FIGS. 2-8 illustrate the various steps of a first exemplary embodimentof a method of forming an optoelectronic device according to thisinvention.

FIG. 2 illustrates a first step of the first exemplary embodiment of themethod of forming an optoelectronic device according to this invention.In this first step, an n-type group III-V layer 23 is epitaxially grownon or over a sapphire substrate 21. The n-type group III-V layer 23 isgrown on or over the sapphire substrate 21 by any suitable method, suchas by metal-organic chemical vapor deposition (MOCVD). In this exemplaryembodiment, the n-type layer group III-V layer 23 is n-type GaN. Then-type group III-V layer 23 is doped with any suitable n-type dopant,such as, for example, Si.

FIG. 3 illustrates a second step of the first exemplary embodiment ofthe method of forming an optoelectronic device according to thisinvention. In this second step, an active layer 24 is grown on or overthe n-type group III-V layer 23. The active layer 24 includes anysuitable material, such as, for example, InGaN.

FIG. 4 illustrates a third step of the first exemplary embodiment of themethod of forming an optoelectronic device according to this invention.In this third step, a p-type group III-V layer 25 is grown on or overthe active layer 24. In this exemplary embodiment, the p-type groupIII-V layer 25 is GaN. The p-type group III-V layer is doped with afirst acceptor and co-doped with a second dopant and/or isovalentimpurity. The first acceptor has a covalent radius that is differentthan the covalent radius of the group III atoms that make up the p-typegroup III-V layer 25 sublattice. If the covalent radius of the firstacceptor is smaller than the covalent radius of the group III atoms, thesecond dopant and/or isovalent impurity has, in various exemplaryembodiments, a larger covalent radius than the covalent radius of thefirst acceptor. In various other exemplary embodiments, the seconddopant or isovalent impurity can have a covalent radius that is largerthan the covalent radius of the group III atoms that make up the p-typegroup III-V layer 25 sublattice. In this case, the smaller firstacceptor atoms are under a local tensile stress in the p-type groupIII-V layer 25 sublattice. The larger second dopant and/or isovalentimpurity atoms are under a local compressive stress in the p-type groupIII-V layer 25 sublattice. In either case, the complex comprising thefirst acceptor and second dopant and/or isovalent impurity isstress-compensated, resulting in enhanced concentration of the acceptorsin the p-type group III-V layer 25 sublattice.

Similarly, if the covalent radius of the first acceptor is larger thanthe covalent radius of the group III atoms, the second dopant and/orisovalent impurity has, in various exemplary embodiments, a smallercovalent radius than the covalent radius of the first acceptor. Invarious other exemplary embodiments, the second dopant and/or isovalentimpurity can have a covalent radius that is smaller than the covalentradius of the group III atoms that make up the p-type group III-V layer25 sublattice. In this case, the larger first acceptor atoms are under alocal compressive stress in the p-type group III-V layer 25 sublattice.The smaller second dopant and/or isovalent impurity atoms are under alocal tensile stress in the p-type group III-V layer sublattice. Ineither case, the complex comprising the first acceptor and second dopantand/or impurity is stress compensated, resulting in enhancedconcentration of the acceptors in the p-type group III-V layer 25sublattice.

In one exemplary embodiment, the p-type group III-V layer 25 is dopedwith Be and co-doped with In. The co-doping of the p-type group III-Vlayer 25 with In is easily accomplished because an In source is readilyavailable from the active layer 24. Since the desired effects rely onlocal stress compensation around the Be atom, approximately one In atom,or more, should be provided for every Be atom. The desired concentrationof In atoms is thus on the order of the acceptor concentration. However,the relative doping concentration is not limited to this relationship,and thus can have any relative doping concentration that providessufficient stress compensation for the intended uses of the resultingmaterial.

FIG. 5 illustrates a fourth step of the first exemplary embodiment ofthe method of forming an optoelectronic device according to thisinvention. In this fourth step, portions of the active layer 24 and thep-type group III-V layer 25 are patterned and/or removed to form anexposed portion 30 of the n-type group III-V layer 23. Removing theportions of the active layer 24 and the p-type group III-V layer 25 toform the exposed portion 30 of the n-type group III-V layer 23 can beaccomplished by any suitable method, such as, for example, etching.

FIG. 6 illustrates a fifth step of the first exemplary embodiment of themethod of forming an optoelectronic device according to this invention.In this fifth step, a first electrode 28 is formed on or over the p-typegroup III-V layer 25. The first electrode 28 includes any suitablematerial, such as, for example, Ti and Al. The first electrode 28 isformed on or over the p-type group III-V layer 25 by any suitablemethod, such as, for example, a process that includes evaporating andsintering of the material used to form the first electrode 28.

FIG. 7 illustrates a sixth step of the first exemplary embodiment of themethod of forming an optoelectronic device according to this invention.In this sixth step, an second electrode 29 is formed on or over theexposed portion 30 of the n-type group III-V layer 23. The secondelectrode 29 includes any suitable material, such as, for example, Tiand Al. The second electrode 29 can be formed on or over the exposedportion 30 of the n-type group III-V layer by any suitable method, suchas, for example, a process that includes evaporating and sintering ofthe material used to form the second electrode 28.

In some, but not all, exemplary embodiments, the n-type group III-Vlayer 23 layer is doped with a first donor and co-doped with a seconddopant and/or isovalent impurity. The first donor has a covalent radiusthat is different than the covalent radius of the group V atoms thatmake up the n-type group III-V layer 23 sublattice. If the covalentradius of the first donor is smaller than the covalent radius of thegroup V atoms, the second dopant and/or isovalent impurity has, invarious exemplary embodiments, a larger covalent radius than thecovalent radius of the first donor. In various other exemplaryembodiments, the second dopant or isovalent impurity can have a covalentradius that is larger than the covalent radius of the group V atoms thatmake up the n-type group III-V layer 23 sublattice. In this case, thesmaller first donor atoms are under a local tensile stress in the n-typegroup III-V layer 23 sublattice. The larger second dopant and/orisovalent impurity atoms are under a local compressive stress in then-type group III-V layer 23 sublattice. In either case, the complexcomprising the first donor and second dopant and/or isovalent impurityis stress-compensated, resulting in enhanced concentration of the donorsin the n-type group III-V layer 23 sublattice.

Similarly, if the covalent radius of the first donor is larger than thecovalent radius of the group V atoms, the second dopant and/or isovalentimpurity has, in various exemplary embodiments, a smaller covalentradius than the covalent radius of the first donor. In various otherexemplary embodiments, the second dopant and/or isovalent impurity canhave a covalent radius that is smaller than the covalent radius of thegroup V atoms that make up the n-type group III-V layer 23 sublattice.In this case, the larger first donor atoms are under a local compressivestress in the n-type group III-V layer 23 sublattice. The smaller seconddopant and/or isovalent impurity atoms are under a local tensile stressin the n-type group III-V layer 23 sublattice. In either case, thecomplex comprising the first donor and second dopant and/or impurity isstress-compensated, resulting in enhanced concentration of the donors inthe n-type group III-V layer 23 sublattice.

In one exemplary embodiment, the n-type group III-V layer 23 is GaAs.The n-type group III-V layer is doped with Te and co-doped with asmaller sized co-dopant, such as, for example, S, on the As site.Alternatively, P isovalent impurities can be introduced on the Assublattice, or B isovalent impurities can be introduced on the Ga siteto compensate for the local stress caused by the larger Te atoms.

It should be appreciated that, in various exemplary semiconductorstructures, when a p-type layer or region is doped according to thisinvention, it is not necessary to dope any related n-type layer orregion according to this invention. Likewise, in some exemplarysemiconductor structures, when an n-type layer or region is dopedaccording to this invention, it is not necessary to dope any relatedp-type layer or region according to this invention. However, in someexemplary semiconductor structures, it may be desirable to dope both then-type and the p-type layers and/or regions according to this invention.

The exemplary embodiments of the methods of doping semiconductormaterial according to this invention results in a higher concentrationof doping atoms in the doped region or layer of a group III-V compoundsemiconductor material. Higher concentrations of the acceptor or donoratoms in the corresponding region of a group III-V semiconductor resultsin improved device efficiency. For example, the exemplary embodiments ofthe methods of doping semiconductor material according to this inventionprovides improved efficiency of electronic devices, such as, forexample, transistors, optoelectronic devices, diodes, laser diodes andlight emitting diodes. Further, the exemplary embodiments of the methodsof doping semiconductor material according to this invention providesimproved efficiency of electronic systems that incorporate suchelectronic devices, such as, for example, display devices, image formingdevices, facsimile machines, laser printers, fiber-optic networks,microprocessors, gate arrays, and digital signal processors.

While this invention has been described in conjunction with the specificexemplary embodiments outlined above, it is evident that manyalternatives, modifications and variations will be apparent to thoseskilled in the art. Accordingly, the exemplary embodiments of theinvention, as set forth above, are intended to be illustrative, notlimiting. Various changes may be made without departing from the spiritand scope of the invention.

What is claimed is:
 1. A semiconductor material, comprising: at leastone group III-V region doped by an n-type dopant; wherein the n-typedopant includes a first n-type dopant and at least one of a secondn-type dopant and an impurity, the first n-type dopant having a covalentradius different in size than a covalent radius of each of the secondn-type dopant and the impurity, such that a local stress in the at leastone group III-V region caused by the first n-type dopant is compensatedby a local stress in the at least one group III-V region caused by theat least one of the second n-type dopant and the impurity, such that aconcentration of the first n-type dopant in the at least one group III-Vregion is enhanced.
 2. The semiconductor material of claim 1, whereinthe at least one group III-V region is at least one of GaAs and InP. 3.The semiconductor material of clam 1, wherein the at least one groupIII-V region is a group III nitride region.
 4. The semiconductormaterial of claim 3, wherein the group III nitride region is GaN.
 5. Thesemiconductor material of claim 1, wherein the n-type dopant comprises afirst n-type dopant and a second n-type dopant.
 6. The semiconductormaterial of claim 5, wherein the first n-type dopant is a relativelylarge covalent radius group VI donor and the second n-type dopant is arelatively small covalent radius group VI donor.
 7. The semiconductormaterial of claim 6, wherein the first n-type dopant has a largercovalent radius than the covalent radius of group V atoms in the atleast one group III-V region, and the second n-type dopant has a smallercovalent radius than the covalent radius of group V atoms in the atleast one group III-V region.
 8. The semiconductor material of claim 6,wherein the first n-type dopant is Te and the second n-type dopant is S.9. The semiconductor material of claim 1, wherein the n-type dopantcomprises a first n-type dopant and an isovalent impurity.
 10. Thesemiconductor material of claim 9, wherein the first n-type dopant is arelatively large covalent radius group VI donor and the isovalentimpurity is a relatively small covalent radius group V isovalentimpurity.
 11. The semiconductor material of claim 10, wherein the firstn-type dopant has a larger covalent radius than the covalent radius ofgroup V atoms in the at least one group III-V region, and the isovalentimpurity has a smaller covalent radius than the covalent radius of groupV atoms in the at least one group III-V region.
 12. The semiconductormaterial of claim 11, wherein the first n-type dopant is Te and theisovalent impurity is P.
 13. The semiconductor material of claim 9,wherein the first n-type dopant is a relatively large covalent radiusgroup VI donor and the isovalent impurity is a relatively small covalentradius group III isovalent impurity.
 14. The semiconductor material ofclaim 13, wherein the first n-type dopant has a larger covalent radiusthan the covalent radius of group V atoms of the at least one groupIII-V region, and the isovalent impurity has a smaller covalent radiusthan the covalent radius of group III atoms of the at least one groupIII-V region.
 15. The semiconductor material of claim 14, wherein thefirst n-type dopant is Te and the isovalent impurity is B.
 16. Anelectronic device containing the semiconductor material of claim
 1. 17.The electronic device of claim 16, wherein the electronic device is oneof a transistor, an optoelectronic device, a diode, a laser diode and alight emitting diode.
 18. An electronic system, containing at least oneelectronic device of claim
 17. 19. The electronic system of claim 18,wherein the electronic system is at least one of a display device, animage forming device, a facsimile machine, a laser printer, afiber-optic network, a microprocessor, a gate array, and a digitalsignal processor.
 20. A semiconductor structure, comprising: asubstrate; at least one first group III-V region formed in, on or overthe substrate, at least a portion of the at least one first group III-Vregion doped by one of an n-type dopant and a p-type dopant; at leastone second group III-V region formed in, on or over the substrate, atleast a portion of the at least one second group III-V region doped bythe other one of the n-type dopant and the p-type dopant; wherein then-type dopant includes a first n-type dopant and at least one of asecond n-type dopant and an impurity, the first n-type dopant having acovalent radius different in size than a covalent radius of each of thesecond n-type dopant and the impurity, such that a local stress in thefirst or second group III-V region caused by the first n-type dopant iscompensated by a local stress in the first or second group III-V regioncaused by the at least one of the second n-type dopant and the impurity,such that a concentration of the first n-type dopant in the first orsecond group III-V region is enhanced.
 21. The semiconductor structureof claim 20, further comprising: a first electrode formed on or over theat least one first group III-V region; and a second electrode formed onor over the at least one second group III-V region.
 22. Thesemiconductor structure of claim 20, wherein at least one of the atleast one first group III-V region and the at least one second groupIII-V region is GaAs.
 23. The semiconductor structure of claim 20,wherein at least one of the at least one first group III-V region andthe at least one second group III-V region is InP.
 24. The semiconductorstructure of claim 20, wherein at least one of the at least one firstgroup III-V region and the at least one second group III-V region is agroup III nitride region.
 25. The semiconductor structure of claim 24,wherein at least one of the the group III nitride regions is GaN. 26.The semiconductor structure of claim 20, wherein the n-type dopantcomprises a first n-type dopant and a second n-type dopant.
 27. Thesemiconductor structure of claim 26, wherein the first n-type dopant isa relatively large covalent radius group VI donor and the second n-typedopant is a relatively small covalent radius group VI donor.
 28. Thesemiconductor structure of claim 27, wherein the first n-type dopant hasa larger covalent radius than the covalent radius of group V atoms inthe first or second group III-V region, and the second n-type dopant hasa smaller covalent radius than the covalent radius of group V atoms inthe first or second group III-V region.
 29. The semiconductor structureof claim 28, wherein the first n-type dopant is Te and the second n-typedopant is S.
 30. The semiconductor structure of claim 20, wherein then-type dopant comprises a first n-type dopant and an isovalent impurity.31. The semiconductor structure of claim 30, wherein the first n-typedopant is a relatively large covalent radius group VI donor and theisovalent impurity is a relatively small covalent radius group Visovalent impurity.
 32. The semiconductor structure of claim 31, whereinthe first n-type dopant has a larger covalent radius than the covalentradius of group V atoms in the first or second group III-V region, andthe isovalent impurity has a smaller covalent radius than the covalentradius of group V atoms in the first or second group III-V region. 33.The semiconductor structure of claim 32, wherein the first n-type dopantis Te and the isovalent impurity is P.
 34. The semiconductor structureof claim 30, wherein the first n-type dopant is a relatively largecovalent radius group VI donor and the isovalent impurity is arelatively small covalent radius group III isovalent impurity.
 35. Thesemiconductor structure of claim 34, wherein the first n-type dopant hasa larger covalent radius than the covalent radius of group V atoms ofthe first or second group III-V region, and the isovalent impurity has asmaller covalent radius than the covalent radius of group III atoms ofthe first or second group III-V region.
 36. The semiconductor structureof claim 35, wherein the first n-type dopant is Te and the isovalentimpurity is B.
 37. An electronic device containing the semiconductordevice of claim
 20. 38. The electronic device of claim 37, wherein theelectronic device is one of a transistor, an optoelectronic device, adiode, a laser diode and a light emitting diode.
 39. An electronicsystem, containing at least one electronic device of claim
 38. 40. Theelectronic system of claim 39, wherein the electronic system is at leastone of a display device, an image forming device, a facsimile machine, alaser printer, a fiber-optic network, a microprocessor, a gate array,and a digital signal processor.
 41. The semiconductor structure of claim20, further comprising an active region formed on or over the at leastone first group III-V region, wherein the second group III-V region is agroup III-V layer formed on or over the active layer.
 42. Thesemiconductor structure of claim 41, wherein the active region is InGaN.